If you lean on the nebulous idea that being born into a society is somehow a contribution to any particular success in general, I'm going to assume you're bullshitting. Fair warning.

With the lack of community and the focus on individual and the self, people will not be fulfilled if they know someone else is doing so much better.

It's the classic monkey experiment with cucumbers. If all monkeys get cucumbers, they are all okay with it. If one monkey gets a cherry while the other gets a cucumber, the cucumber monkey feels it's unfair and gets angry.

You can keep humans in shitty conditions if they believe in something bigger than themselves. That the shitty conditions are justified and therefore fair.

Ha! If you genuinely want to hear people (very passionately) make this argument, try proposing a higher estate tax

Many countries have very low (or zero) tax rates, so you can legally set up a company and put your money there.

I think one way to get rid of tax havens is with an international treaty to set some minimum tax rates, and have an embargo against any country that doesn't meet those requirements. It's not just the rich who are to blame, it's the countries that turn themselves into tax havens and make this all possible.